Municipal and other types of water towers may include pumps for pumping water into the water towers, but using electricity to pump water into the water towers requires substantial expense. At night, when the demand for water typically is less, the rates for purchasing power from the electric power grid frequently are off-peak and lower. Therefore, pumping water into the water towers during off-peak times may reduce the cost of running the pumps. However, pumping water into the water towers still requires substantial expense, and for some water towers, it is often unavoidable to pump water into the water towers during peak times. The disclosed power generation system is directed to overcoming one or more of the problems of the existing technology, as will be described below.